[JENKINS-17850] Add multiple Gerrit server support

Refactor methods related to one Gerrit server to a new class GerritServer and
keep a list of GerritServer objects in PluginImpl.
Refactor all related classes and tests.

Change-Id: I11d3f0d694b3670e879a6ecf10513967603c6e13
Fix merge conflict.

Conflicts:
	gerrithudsontrigger/src/test/java/com/sonyericsson/hudson/plugins/gerrit/trigger/spec/DuplicateGerritListenersHudsonTestCase.java

Change-Id: I44da83088dc1f5e8754c59c0633a6914676ac1a7
Fix tests.

Change-Id: Id9032918ebc195b3ab4131ebb2cc10a279bfbc70
Move server list initialization to PluginImpl.load()

Change-Id: I654047037105e80547da08f7fcc23110d108daa4
Merge Github master.

Change-Id: Iaa0bb645df5d411ac5c308071d205bd47a8de3d4
Refactor the GerritManagement page and add null checks.

Changes:
1.The GerritManagement page only shows the list of servers now.
The configurations for each server have been moved to GerritServer/index.jelly.
2.Add null checks for methods calling PluginImpl#getServer.
3.Use a LinkedList instead of ArrayList for GerritServers in PluginImpl.
4.Initial (yet disabled) code to eventually support server renaming
(See TODO comments in GerritServer#doConfigSubmit).

Change-Id: I1917c320b16bfe7270773ea4a851712b2350f573
Fix test error in ManualTriggerActionPermissionTest.

Change-Id: I248345fa30a1d89cf13ca0e2e6d1326954bfc105
Enable server renaming.

The jobs configured with the old server will also have
their configurations changed and saved.

Change-Id: Ice25698c2c61b680d540f21d288a747410c036ba
Fix empty verdict category list in "comment added" events.

Make verdict category dropdown update dynamically depending on selected server.

Change-Id: Ie829882724fb2141b1fdcaf2ca3fec4b7086a71c
Prohibit removal of the last server.

Change-Id: Ifbe6bf25b1bdd7b1940378d0d418563c2a5de374
Add null check for getServer in GerritManagement.

Change-Id: I668bc7a0a12c8baa53774c6d2e4fad54b9758d4d
Fix creation of new server from existing config.

Start and save server immediately after creation.

Change-Id: I8e47a1fedeadaa007a915876f7757f16279fca83
Add auto-completion to "Copy Server From".

Change-Id: I4f035dfaa57c9021bc9d739e8be2d02877be2656
Increase time-out limits to make tests pass more easily.

Move initializeListeners to avoid Admin Monitor problems

Change-Id: I52f52f3a8b4b7187433f1fb5b3242d1a02811d1e
Fix Manual Query.

Change-Id: I8294900ee0db28f8ebce56184b186c5e407fba4c
Add check for retrigger after rename.

Change-Id: I2182e93e3882be58bdbd5eb229f6971b7a5d1374
Fix unreviewed patches NPE by adding serverName info to event provider.

Change-Id: I459a48dc4c2e901fd8bbd1305c60a1cb0cfc2c5c
Merge pull request #68 from mathieu-wang/master

[JENKINS-17850] Add multiple Gerrit server support